He said: "I compared a graph of full moons and a graph of last year's violent crimes and there is a trend. Even if only one extra officer is put on the shift it can help prevent violent crime.

"Drinkers also tended to be more aggressive and unhelpful during the full moon."

He identified full moons and paydays as key dates when aggression rises in pubs and clubs.

Insp Parr of Sussex Police has ordered more officers to patrol Brighton's streets when the moon is full.

A police spokeswoman said: "This is not scientifically proven but there is a correlation."

Psychologist Dr Keith Ashcroft said: "There is no scientific proof to link the lunar cycle with how people act. Studies show a rise in admissions to psychiatric hospitals, but there's no reason to explain it."

Criminologist Dr Paul Kiff, of the University of East London, said more light during a full moon could explain the link.

He added: "There is more chance to commit crimes such as muggings, rapes and car thefts.

"It is interesting there doesn't seem to be a rise in burglaries because they rely on darkness.

"And there is probably more violence on paydays simply because people have more money to spend and get more drunk."

But other experts are convinced there is a lunar link. One theory is that the water content in the human body means it is affected by lunar gravity just like the sea.

A study at Armley jail in Leeds in 1998 found a rise in violence either side of a full moon.